While driving along the ride is resonably smooth but when i reach around 50mph the whole car starts to vibrate (not just through the wheel) and gets worse the faster i go. if i back off the throttle the vibration disappears until i re-apply it. This makes me think its an engine issue when put under a certain load. Plugs, HT leads, fuel filter and inlet gasket replaced only a few months ago and the coil pack replaced about 1-1 1/2 years ago.

Any thoughts on the problem would be appriciated

Thanks

Sounds like engine mounts? if you run at high revs in the town driving, do you notice the vibration then, or when stationary?

If not then it could be warped brake disk/s?

Engine or gearbox mounts.

Also could be tyre tread or suspension geometry.

Thanks for you quick replys

I dont notice the vibration at high revs either when town driving or stationary, just when at speed. Would this point more towards suspension at fault?

start off checking the mounts as Stoney suggested, slow traffic means that things arent going to be bouncing around, and if you hit a pothole thats what you will feel, so at high speeds, the rattle / vibration is more likely to be noticed.

Could be a bent driveshaft.... Also could be buckeled tyres, there is endless sugestions as too what it could be but you wont get an exact diagnosis without seeing mechanic